Attitude-sensing ultrasound probe

Abstract

In one embodiment, an apparatus for generating attitude data corresponding to B-scan imaging data generated by an ultrasound probe. The apparatus includes one or more magnetic field sensors generating, based on measurements of the earth's magnetic field, magnetic field data for the probe, which is used to determine the orientation of the probe in a plane. The apparatus preferably also includes one or more accelerometers for determining tilt orientation and position. The apparatus further includes an interface providing, based on the magnetic field data, output data corresponding to the imaging data. The apparatus can be integrated into a probe or can be an attachment to retrofit an existing probe.

1 . Apparatus for generating data corresponding to attitude of a probe generating imaging data, the apparatus comprising:
 one or more magnetic field sensors adapted to generate, based on measurements of the earth's magnetic field, magnetic field data for the probe; and   an interface adapted to provide, based on the magnetic field data, output data corresponding to the imaging data, wherein the output data identifies the attitude of the probe during generation of the imaging data.   
   
   
       2 . The invention of  claim 1 , further comprising one or more acceleration sensors adapted to generate acceleration data corresponding to the imaging data and further identifying the attitude of the probe, wherein the output data provided by the interface is further based on the acceleration data. 
   
   
       3 . The invention of  claim 1 , wherein:
 the apparatus comprises the probe; and   the probe, the one or more magnetic field sensors, and the interface are integrated in a single device.   
   
   
       4 . The invention of  claim 1 , wherein:
 the apparatus is adapted to be removably attached to the probe; and   the one or more magnetic field sensors and the interface are integrated in a single device that is adapted to retrofit an existing probe.   
   
   
       5 . The invention of  claim 1 , further comprising a calibration switch, wherein the apparatus is adapted, upon activation of the calibration switch, to identify current magnetic field data as baseline magnetic field data. 
   
   
       6 . The invention of  claim 1 , further comprising a processor adapted to use the magnetic field data to generate an indicator of at least one of position and orientation relative to an eye being imaged by the probe. 
   
   
       7 . The invention of  claim 1 , further comprising:
 a calibration switch; and   a processor adapted:   (i) upon activation of the calibration switch, to identify current magnetic field data as baseline magnetic field data, and   (ii) to generate subsequent output data by comparing subsequent measurements of the earth's magnetic field to the baseline magnetic field data.   
   
   
       8 . The invention of  claim 1 , wherein:
 the one or more magnetic field sensors comprise two magnetic field sensors disposed so as to sense orientation in two substantially mutually-perpendicular directions relative to the earth's magnetic north; and   the magnetic field data indicates orientation of the probe in a plane.   
   
   
       9 . The invention of  claim 1 , wherein the interface is (i) a universal serial bus (USB) interface for interfacing with a computer having a USB bus or (ii) a wireless interface. 
   
   
       10 . The invention of  claim 1 , wherein the output data comprises one or more indicators corresponding to scan type and clock hour for a B-scan of an eye. 
   
   
       11 . The invention of  claim 1 , further comprising:
 one or more acceleration sensors adapted to generate acceleration data corresponding to the imaging data and further identifying the attitude of the probe, wherein the output data provided by the interface is further based on the acceleration data;   a calibration switch; and   a processor for processing the magnetic field data and the acceleration data, wherein the processor is adapted:
 (i) upon activation of the calibration switch, to identify (1) current magnetic field data as baseline magnetic field data and (2) current acceleration data as baseline acceleration data, and 
 (ii) to generate subsequent output data by comparing (1) subsequent magnetic field data to the baseline magnetic field data and (2) subsequent acceleration data to the baseline acceleration data. 
   
   
   
       12 . The invention of  claim 11 , wherein the processor is adapted to generate and output an indicator of position and orientation relative to an eye being imaged by the probe based on the comparisons of (1) the subsequent magnetic field data with the baseline magnetic field data and (2) the subsequent acceleration data with the baseline acceleration data. 
   
   
       13 . A method for generating data corresponding to attitude of a probe generating imaging data, the method comprising:
 generating, based on measurements of the earth's magnetic field, magnetic field data for the probe; and   providing, based on the magnetic field data, output data corresponding to the imaging data, wherein the output data identifies the attitude of the probe during generation of the imaging data.   
   
   
       14 . The invention of  claim 13 , further comprising generating acceleration data corresponding to the imaging data and further identifying the attitude of the probe, wherein the output data is further based on the acceleration data. 
   
   
       15 . The invention of  claim 13 , further comprising identifying current magnetic field data as baseline magnetic field data based on activation of a calibration switch. 
   
   
       16 . The invention of  claim 13 , further comprising processing the magnetic field data to generate an indicator of orientation relative to one or more body parts being imaged by the probe. 
   
   
       17 . The invention of  claim 16 , wherein the one or more body parts is an eye. 
   
   
       18 . The invention of  claim 13 , further comprising:
 (i) identifying current magnetic field data as baseline magnetic field data based on activation of a calibration switch; and   (ii) generating subsequent output data by comparing subsequent measurements of the earth's magnetic field to the baseline magnetic field data.   
   
   
       19 . The invention of  claim 13 , wherein:
 (i) the step of generating the magnetic field data for the probe comprises sensing orientation in two substantially mutually-perpendicular directions relative to the earth's magnetic north; and   (ii) the magnetic field data indicates orientation of the probe in a plane.   
   
   
       20 . The invention of  claim 13 , further comprising providing the output data (i) via a universal serial bus (USB) interface to a computer having a USB bus or (ii) via a wireless interface. 
   
   
       21 . The invention of  claim 13 , wherein the output data comprises one or more indicators corresponding to scan type and clock hour for a B-scan of an eye. 
   
   
       22 . The invention of  claim 13 , wherein the output data is generated without inducing a magnetic field that substantially affects the magnetic field data, such that the only substantial magnetic field used to generate the output data is the earth's magnetic field. 
   
   
       23 . The invention of  claim 13 , further comprising:
 generating acceleration data (i) corresponding to the imaging data and (ii) further identifying the attitude of the probe, wherein the output data is further based on the acceleration data;   upon activation of a calibration switch, identifying (1) current magnetic field data as baseline magnetic field data and (2) current acceleration data as baseline acceleration data, and   generating subsequent output data by comparing (1) subsequent magnetic field data to the baseline magnetic field data and (2) subsequent acceleration data to the baseline acceleration data.   
   
   
       24 . The invention of  claim 23 , further comprising generating and outputting an indicator of position and orientation relative to an eye being imaged by the probe based on the comparisons of (1) the subsequent magnetic field data with the baseline magnetic field data and (2) the subsequent acceleration data with the baseline acceleration data. 
   
   
       25 . Apparatus for generating output data corresponding to attitude of a probe generating imaging data, the apparatus comprising:
 one or more sensors adapted to generate attitude measurements for the probe;   a calibration switch;   a processor adapted, upon activation of the calibration switch, to identify current attitude measurements as baseline attitude measurements; and   an interface adapted to provide the output attitude data based on subsequent attitude measurements and the baseline attitude measurements.   
   
   
       26 . The invention of  claim 25 , wherein:
 the processor compares the subsequent attitude measurements to the baseline attitude measurements to determine position and orientation of the probe; and   the output attitude data comprises one or more indicators corresponding to scan type and clock hour for a B-scan of an eye.   
   
   
       27 . A method for generating output attitude data corresponding to imaging data generated by a probe, the method comprising:
 generating attitude measurements for the probe;   upon activation of a calibration switch, identifying current attitude measurements as baseline attitude measurements; and   providing the output attitude data based on subsequent attitude measurements and the baseline attitude measurements.   
   
   
       28 . The invention of  claim 27 , further comprising:
 comparing the subsequent attitude measurements to the baseline attitude measurements to determine position and orientation of the probe, wherein the output attitude data comprises one or more indicators corresponding to scan type and clock hour for a B-scan of an eye.